body {
  font-size: 14px;
  color: white;
  font-family: 'Microsoft YaHei', 'Times New Roman', Times, serif;
  background: rgba(72, 255, 0, 0.5);
  padding: 0;
  margin: 0;
  background-size: cover;
  -webkit-background-size: cover;
  -moz-background-size: cover;
  transition: background 1s ease-in-out;
}

.clock {
  list-style: none;
  margin: auto;
  padding: 0;
  width: 700px;
  height: 700px;
  position: fixed;
  top: 0;
  right: 0;
  bottom: 0;
  left: 0;
  line-height: 20px;

  user-select: none;
}

.clock .date {
  position: absolute;
  z-index: 1;
  width: 100%;
  height: 20px;
  text-align: center;
  top: 340px;
  left: 0;
}
.clock .hour {
  position: absolute;
  z-index: 3;
  width: 360px;
  height: 20px;
  top: 340px;
  left: 170px;
  transition: transform 0.3s ease-in-out 0s;
  transform: rotate(0deg);
}
.clock .hour > div {
  position: absolute;
  width: 100%;
  right: 0;
  top: 0;
  transition: transform 1s ease-in-out 0s;
  transform: rotate(0deg);
}
.clock .hour > div > div {
  float: right;
  width: 60px;
  text-align: right;
}

.clock .minute {
  position: absolute;
  z-index: 4;
  width: 520px;
  height: 20px;
  top: 340px;
  left: 90px;
}
.clock .sec {
  position: absolute;
  z-index: 5;
  width: 680px;
  height: 20px;
  top: 340px;
  left: 10px;
}

.clock > hr {
  height: 0;
  width: 0%;
  position: absolute;
  z-index: 1;
  border: #ff0000 solid 0;
  border-bottom-width: 2px;
  margin: 10px 0 0 0;
  left: 50%;
  top: 50%;
  transition: width 0.3s ease-in-out 0s;
  overflow: visible;
}
.clock > hr.active:before {
  content: '';
  display: block;
  width: 5px;
  height: 5px;
  border-radius: 50%;
  background-color: yellow;
  top: -2px;
  left: 0;
  position: absolute;
}
